Zinc Oxide Specification For 99.0% (Min.) Purity Specifications are as Follows 1.Purity ,%age by Weight (Min.) - 99.0% 2.Sieve Residue, % by mass thro' 325 Mesh (45 microns)(Max.)- 0.050 3.Surface Area, Sq mtr / gm., - 4.0 to 6.0 4.pH Value (10gm/100ml ) - 5.0 to 8.0 5.Loss on Ignition at 950°C, % by mass (Max) - 0.35 6.Relative Density / Sp Gravity, At 27 / 27 °C - 5.50 ~ 5.65 7.Moisture Content at 105°C ± 2°C for two hours, % by mass (Max) - 0.20 8.Matter insoluble in HCl, % by mass (Max.) - 0.05 9.Lead (as Pb), ppm (Max.) - 2000.00 10. Cadmium (as Cd),ppm (Max.) -